From 52b20f4a2808dc6732fd9d185a9f0b3c1122b7e0 Mon Sep 17 00:00:00 2001
From: Stefan Rueger <stefan.rueger@open.ac.uk>
Date: Thu, 28 Apr 2022 17:26:09 +0100
Subject: [PATCH] Provide self-documenting API for disabling trailing-0xff
 removal

---
 src/arduino.c    | 3 +--
 src/libavrdude.h | 1 +
 src/main.c       | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/arduino.c b/src/arduino.c
index 7f030a13..f7b60246 100644
--- a/src/arduino.c
+++ b/src/arduino.c
@@ -131,6 +131,5 @@ void arduino_initpgm(PROGRAMMER * pgm)
   pgm->open = arduino_open;
   pgm->close = arduino_close;
 
-  /* disable trailing-0xff removal when reading input files and avr flash */
-  avr_mem_hiaddr(NULL);
+  disable_trailing_ff_removal(); /* so that arduino bootloader can ignore chip erase */
 }
diff --git a/src/libavrdude.h b/src/libavrdude.h
index ddb72b48..d8d5739a 100644
--- a/src/libavrdude.h
+++ b/src/libavrdude.h
@@ -787,6 +787,7 @@ int avr_get_cycle_count(PROGRAMMER * pgm, AVRPART * p, int * cycles);
 
 int avr_put_cycle_count(PROGRAMMER * pgm, AVRPART * p, int cycles);
 
+#define disable_trailing_ff_removal() avr_mem_hiaddr(NULL)
 int avr_mem_hiaddr(AVRMEM * mem);
 
 int avr_chip_erase(PROGRAMMER * pgm, AVRPART * p);
diff --git a/src/main.c b/src/main.c
index c3bc0381..526ae35f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -528,7 +528,7 @@ int main(int argc, char * argv [])
 
       case 'D': /* disable auto erase */
         uflags &= ~UF_AUTO_ERASE;
-        avr_mem_hiaddr(NULL); /* disable trailing 0xff optimisation */
+        disable_trailing_ff_removal();
         break;
 
       case 'e': /* perform a chip erase */